Is it permissible for a donor to reclaim land he donated to the Ministry of Health 14 years ago, on which no hospital has been built yet?

If the donor intended to dedicate the land as a waqf for building a hospital, and the wording of the donation indicated a waqf, then he is not permitted to revoke his waqf. If the Ministry is unable to build the hospital, it can be built by another entity. Otherwise, the purpose of the waqf can be changed to be used for another charitable deed that benefits Muslims, or the land can be sold and its proceeds used for another waqf. However, if the donor did not intend a waqf, but rather wished to give it as a charity or a gift conditioned upon the building of a hospital, and the condition was not met, then there is no harm for him in revoking it. It is commendable for him to donate it for another good cause and not reclaim it for himself, following the example of Ibn Umar (may Allah be pleased with them both).